Reddit user got a tour of the Cape and learned a few things

[Grendal]

Reddit user Nexuswolf posted the following:
Got a lot of good information. Here's the major points

• Work being done on FSS for crew. More clean looking.
  
  
• Some work being done on flame trench, no specifics.
  
  
• Zip line escape system from tower to west side of pad.
  
  
• Telstar will be a block 5 booster.
  
  
• In-flight abort will be a block 5 booster, will be that boosters third flight.
  
  
• New campus will be built for BFR housing.
  
  
• Dragon 2 arrives at the Cape around mid July (13th?)
  
  
• Dragon 2 will be reused many times.
  
  
• 3 Falcon 9's currently in the hangar, one is a brand new Block 5, two are flown. One is the TESS booster.
  
  
• 24 Hour turnaround demo will be in 2019
  
  
• Block 5 boosters are reinforced straight from factory for use on FH flights.
  
  
• Consistent 5 day turnaround(ish) within year and a half.
  
  
• No S2 recovery plans in work yet.

r/spacex - Here is what I got from my tour!

The biggest bombshell in these is the use of a Block 5 for the In Flight Abort. I expect that to be B5 core B1046 since that has already been flown once.

 

[Cosmacelf]

Presumably that means they will land the flight abort booster? Efficient way to perform a test! I wonder what they will do with the second stage on the flight abort test? Land the booster with the second stage still attached?

 

[ecarfan]

The biggest bombshell in these is the use of a Block 5 for the In Flight Abort.

Absolute. I was suprised and pleased to read that.

I wonder what they will do with the second stage on the flight abort test? Land the booster with the second stage still attached?

It does seem unlikely that SpaceX would waste a second stage for that test. But SpaceX has never attempted to land a booster with the first stage attached. Can they do that?

However, since the abort test flight isn’t going to orbit, the second stage rocket isn’t needed. Would it be possible to mount Crew Dragon and trunk on top of the interstage and not even use a second stage?

I have a lot of questions and no answers.

 

[mongo]

Absolute. I was suprised and pleased to read that.

It does seem unlikely that SpaceX would waste a second stage for that test. But SpaceX has never attempted to land a booster with the first stage attached. Can they do that?

However, since the abort test flight isn’t going to orbit, the second stage rocket isn’t needed. Would it be possible to mount Crew Dragon and trunk on top of the interstage and not even use a second stage?

I have a lot of questions and no answers.

You and me both!

All deviations from stock configuration create potential issues. Mass, CG, all point to use of real 2nd stage with fuel. Otherwise, they need to bypass self checks in SW and then adjust throttle usage (if dummy mass not used).

That said, they may be able to put an aerodynamic nose cone on the 2nd stage. Then there is still the issue with being a non-representative test. Maybe the 2nd stage does something bad on Dragon separation. Unless they always build with the cone?

I wonder how they are going to use up the normal amount of first stage fuel.

So I'm going with aerodynamic cone between Crew Dragon and 2nd stage. Dragon separates, Block 5 continues normal profile, 2nd stage splits off, first stage returns.

 

[Grendal]

It does seem unlikely that SpaceX would waste a second stage for that test. But SpaceX has never attempted to land a booster with the first stage attached. Can they do that?

However, since the abort test flight isn’t going to orbit, the second stage rocket isn’t needed. Would it be possible to mount Crew Dragon and trunk on top of the interstage and not even use a second stage?

I have a lot of questions and no answers.

It's my understanding that SpaceX volunteered to do the In Flight Abort and that it was not part of the Commercial Crew contract. So I am surprised SpaceX is risking a Block 5. The speculation I've read says that SpaceX will make a dummy interstage to place on top of the booster. I'm not sure how well that will work though. Wouldn't it throw off the balance? Since they are using a B5, then we can be sure that SpaceX will attempt to recover it. I am now very curious whether SpaceX will use an actual 2nd stage.

We'll see what happens. And whatever it is, it's going to be a wild ride.

 

[Cosmacelf]

Presumably what they put in as a second stage, be it a dummy or whatever, isn’t that critical. I mean, the F9 has to perform now with payloads of varying weight and vastly different flight trajectories.

 

[mongo]

Presumably what they put in as a second stage, be it a dummy or whatever, isn’t that critical. I mean, the F9 has to perform now with payloads of varying weight and vastly different flight trajectories.

True, but the system expects to have a 2nd stage with a bunch of parameters. Either the software needs to ignore the errors, or they have to simulate the data stream. System mass is only one aspect, and within that the payload is a fraction of the whole: max LEO payload is 5% of total mass.